SM 25x275 [2xM8] / N42 - magnetic separator

Pros as well as cons of NdFeB magnets.

Apart from their superior magnetic energy, neodymium magnets have these key benefits:

• They have unchanged lifting capacity, and over around ten years their attraction force decreases symbolically – ~1% (in testing),
• They show high resistance to demagnetization induced by external magnetic fields,
• In other words, due to the metallic surface of gold, the element is aesthetically pleasing,
• Magnetic induction on the surface of the magnet remains extremely intense,
• Made from properly selected components, these magnets show impressive resistance to high heat, enabling them to function (depending on their form) at temperatures up to 230°C and above...
• Thanks to the potential of free forming and adaptation to specialized solutions, neodymium magnets can be manufactured in a wide range of forms and dimensions, which expands the range of possible applications,
• Versatile presence in modern industrial fields – they find application in magnetic memories, electric drive systems, medical devices, also complex engineering applications.
• Compactness – despite small sizes they offer powerful magnetic field, making them ideal for precision applications

Cons of neodymium magnets: tips and applications.

• They are prone to damage upon heavy impacts. To avoid cracks, it is worth securing magnets in special housings. Such protection not only protects the magnet but also increases its resistance to damage
• Neodymium magnets demagnetize when exposed to high temperatures. After reaching 80°C, many of them experience permanent weakening of strength (a factor is the shape as well as dimensions of the magnet). We offer magnets specially adapted to work at temperatures up to 230°C marked [AH], which are very resistant to heat
• Magnets exposed to a humid environment can corrode. Therefore during using outdoors, we advise using water-impermeable magnets made of rubber, plastic or other material protecting against moisture
• Due to limitations in realizing threads and complicated forms in magnets, we recommend using a housing - magnetic holder.
• Health risk related to microscopic parts of magnets are risky, if swallowed, which is particularly important in the context of child health protection. Furthermore, tiny parts of these magnets are able to be problematic in diagnostics medical in case of swallowing.
• With mass production the cost of neodymium magnets is a challenge,

Magnetic strength at its maximum – what contributes to it?

Information about lifting capacity is the result of a measurement for ideal contact conditions, taking into account:

• using a plate made of high-permeability steel, acting as a ideal flux conductor
• possessing a thickness of minimum 10 mm to avoid saturation
• characterized by smoothness
• under conditions of gap-free contact (metal-to-metal)
• during pulling in a direction vertical to the mounting surface
• in stable room temperature

Impact of factors on magnetic holding capacity in practice

During everyday use, the actual holding force depends on many variables, listed from most significant:

• Distance – the presence of foreign body (rust, tape, air) interrupts the magnetic circuit, which reduces power rapidly (even by 50% at 0.5 mm).
• Loading method – catalog parameter refers to detachment vertically. When applying parallel force, the magnet holds much less (often approx. 20-30% of maximum force).
• Base massiveness – too thin steel causes magnetic saturation, causing part of the power to be wasted to the other side.
• Material composition – different alloys attracts identically. Alloy additives weaken the attraction effect.
• Surface condition – ground elements guarantee perfect abutment, which improves field saturation. Rough surfaces weaken the grip.
• Temperature – temperature increase causes a temporary drop of induction. It is worth remembering the thermal limit for a given model.

* Holding force was tested on a smooth steel plate of 20 mm thickness, when the force acted perpendicularly, whereas under attempts to slide the magnet the holding force is lower. Moreover, even a slight gap {between} the magnet’s surface and the plate lowers the holding force.